Question: If $a + b = -4$ and $x + y + z = -4$, what is $5a + 8z + 8y + 5b + 8x$ ?
Solution: $= 5a + 5b + 8x + 8y + 8z$ $= (5) \cdot (a + b) + (8) \cdot (x + y + z)$ $= (5) \cdot (-4) + (8) \cdot (-4)$ $= -20 - 32$ $= -52$